The Role of Prevotella Species in Female Genital Tract Infections.

Female genital tract infections (FGTIs) include vaginal infections (e.g., bacterial vaginosis [BV]), endometritis, pelvic inflammatory disease [PID], and chorioamnionitis [amniotic fluid infection]. They commonly occur in women of reproductive age and are strongly associated with multiple adverse health outcomes including increased risk of HIV/sexually transmitted infection acquisition and transmission, infertility, and adverse birth outcomes such as preterm birth. These FGTIs are characterized by a disruption of the cervicovaginal microbiota which largely affects host immunity through the loss of protective, lactic acid-producing Lactobacillus spp. and the overgrowth of facultative and strict anaerobic bacteria. Prevotella species (spp.), anaerobic Gram-negative rods, are implicated in the pathogenesis of multiple bacterial FGTIs. Specifically, P. bivia, P. amnii, and P. timonensis have unique virulence factors in this setting, including resistance to antibiotics commonly used in treatment. Additionally, evidence suggests that the presence of Prevotella spp. in untreated BV cases can lead to infections of the upper female genital tract by ascension into the uterus. This narrative review aims to explore the most common Prevotella spp. in FGTIs, highlight their important role in the pathogenesis of FGTIs, and propose future research in this area.

Comparison of the telephone-Montreal Cognitive Assessment (T-MoCA) and Telephone Interview for Cognitive Status (TICS) as screening tests for early Alzheimer's disease.

INTRODUCTION: Remote screening for cognitive impairment associated with Alzheimer's disease (AD) has grown in importance with the expected rise in prevalence of AD in an aging population and with new potential treatment options. METHODS: The Telephone Interview for Cognitive Status (TICS) and new telephone adaptation of the Montreal Cognitive Assessment (T-MoCA) were administered to participants independently classified through in-person clinical evaluation as cognitively normal (CN; n = 167), mild cognitive impairment (MCI; n = 25), or dementia (n = 23). Cerebrospinal fluid AD biomarkers were measured (n = 79). RESULTS: TICS and T-MoCA were highly correlated (r = 0.787; P < 0.001): groups differed on both (CN

Tracing TET1 expression in prostate cancer: discovery of malignant cells with a distinct oncogenic signature.

BACKGROUND: Ten-eleven translocation methylcytosine dioxygenase 1 (TET1) is involved in DNA demethylation and transcriptional regulation, plays a key role in the maintenance of stem cell pluripotency, and is dysregulated in malignant cells. The identification of cancer stem cells (CSCs) driving tumor growth and metastasis is the primary objective of biomarker discovery in aggressive prostate cancer (PCa). In this context, we analyzed TET1 expression in PCa. METHODS: A large-scale immunohistochemical analysis of TET1 was performed in normal prostate (NOR) and PCa using conventional slides (50 PCa specimens) and tissue microarrays (669 NOR and 1371 PCa tissue cores from 371 PCa specimens). Western blotting, RT-qPCR, and 450 K methylation array analyses were performed on PCa cell lines. Genome-wide correlation, gene regulatory network, and functional genomics studies were performed using publicly available data sources and bioinformatics tools. RESULTS: In NOR, TET1 was exclusively expressed in normal cytokeratin 903 (CK903)-positive basal cells. In PCa, TET1 was frequently detected in alpha-methylacyl-CoA racemase (AMACR)-positive tumor cell clusters and was detectable at all tumor stages and Gleason scores. Pearson's correlation analyses of PCa revealed 626 TET1-coactivated genes (r > 0.5) primarily encoding chromatin remodeling and mitotic factors. Moreover, signaling pathways regulating antiviral processes (62 zinc finger, ZNF, antiviral proteins) and the pluripotency of stem cells were activated. A significant proportion of detected genes exhibited TET1-correlated promoter hypomethylation. There were 161 genes encoding transcription factors (TFs), of which 133 were ZNF-TFs with promoter binding sites in TET1 and in the vast majority of TET1-coactivated genes. CONCLUSIONS: TET1-expressing cells are an integral part of PCa and may represent CSCs with oncogenic potential.

Exploration of potential mechanisms of hepatitis C virus resistance in exposed uninfected intravenous drug users.

A rare outcome following exposure to hepatitis C virus (HCV) is a lack of observable infection as clinically measured by HCV RNA- or HCV-recognizing antibodies. The population who exhibit this trait is termed exposed uninfected (EU). Increasing evidence has refined characterization of these individuals, distinct from those who become infected but spontaneously clear HCV. Study of the EU population is highly pertinent for the discovery of antiviral mechanisms of resistance that can reveal antiviral therapeutic strategies. This review provides an overview of similarities and differences of the EU population relative to spontaneous resolvers and the majority whom develop chronic HCV infection, and focusses on possible mechanisms of resistance including innate and adaptive immunity, genetics and lipid interactions.

Hepatitis C virus and atherosclerosis: A legacy after virologic cure?

Hepatitis C virus (HCV) is a major pathogen with approximately 3% of the world's population (over 170 million) infected. Epidemiological studies have shown HCV is associated with an increased risk of cardiovascular and cerebrovascular mortality as well as peripheral arterial disease. This is despite HCV inducing an ostensibly favourable lipid profile with accompanying low classical risk score for atherosclerosis (AS). We discuss possible factors involved in the aetiopathogenesis of atherosclerosis in chronic HCV and hypothesise that an important mechanism underlying the development of AS is the presence of circulating low-density immune complexes that induce an inflammatory response. We suggest that HCV particles may be inducing an antibody response to lipoproteins present in the lipoviral particles and sub-viral particles - a concept similar to the more general 'autoantibody' response to modified LDL. After virologic cure some AS risk factors will recede but an increase in serum cholesterol could result in progression of early atherosclerotic lesions, leaving a legacy from persistent HCV infection that has clinical and therapeutic implications.

Matching of feedback inhibition with excitation ensures fidelity of information flow in the anterior piriform cortex.

Odor-evoked responses in mitral cells of the olfactory bulb are characterized by prolonged patterns of action potential (spike) activity. If downstream neurons are to respond to each spike in these patterns, the duration of the excitatory response to one spike should be limited, enabling cells to respond to subsequent spikes. To test for such mechanisms, we performed patch-clamp recordings in slices of the mouse anterior piriform cortex. Mitral cell axons in the lateral olfactory tract (LOT) were stimulated electrically at different intensities and with various frequency patterns to mimic changing input conditions that the piriform cortex likely encounters in vivo. We found with cell-attached measurements that superficial pyramidal (SP) cells in layer 2 consistently responded to LOT stimulation across conditions with a limited number (1-2) of spikes per stimulus pulse. The key synaptic feature accounting for the limited spike number appeared to be somatic inhibition derived from layer 3 fast-spiking cells. This inhibition tracked the timing of the first spike in SP cells across conditions, which naturally limited the spike number to 1-2. These response features to LOT stimulation were, moreover, not unique to SP cells, also occurring in a population of fluorescently labeled interneurons in glutamic acid decarboxylase 65-eGFP mice. That these different cortical cells respond to incoming inputs with 1-2 spikes per stimulus may be especially critical for relaying bulbar information contained in synchronized oscillations at beta (15-30Hz) or gamma (30-80Hz) frequencies.

Lipids and HCV.

Chronic hepatitis C virus (HCV) infection is associated with an increase in hepatic steatosis and a decrease in serum levels of total cholesterol, low-density lipoprotein cholesterol (LDL) and apolipoprotein B (apoB), the main protein constituent of LDL and very low-density lipoprotein (VLDL). These changes are more marked in HCV genotype 3 infection, and effective treatment results in their reversal. Low lipid levels in HCV infection correlate not only with steatosis and more advanced liver fibrosis but also with non-response to interferon-based therapy. The clinical relevance of disrupted lipid metabolism reflects the fact that lipids play a crucial role in the life cycle of hepatitis C virus. HCV assembly and maturation in hepatocytes depend on microsomal triglyceride transfer protein and apoB in a manner that parallels the formation of VLDL. VLDL production from the liver occurs throughout the day with an estimated 10(18) particles produced every 24 h whilst the estimated hepatitis C virion production rate is 10(12) virions per day. HCV particles in the serum exist as a mixture of complete low-density infectious lipo-viral particles (LVP) and a vast excess of apoB-associated empty nucleocapsid-free sub-viral particles that are complexed with anti-HCV envelope antibodies. Apolipoprotein E (apoE) is also involved in HCV particle morphogenesis and is an essential apolipoprotein for HCV infectivity. ApoE is a critical ligand for the receptor-mediated removal of triglyceride rich lipoprotein (TRL) remnants by the liver. The dynamics of apoB-associated lipoproteins, including HCV-LVP, change post-prandially with an increase in large TRL remnants and very low density HCV-LVP which are rapidly cleared by the liver (at least three HCV receptors are cellular receptors for uptake of TRL remnants). In summary, HCV utilises triglyceride-rich lipoprotein pathways within the liver and the circulation to its advantage.

Crystalline bacterial biofilm formation on urinary catheters by urease-producing urinary tract pathogens: a simple method of control.

The problem of catheter encrustation stems from infection by urease-producing bacteria. These organisms generate ammonia from urea, elevate the pH of urine and cause crystals of calcium and magnesium phosphates to form in the urine and the biofilm that develops on the catheter. In this study, a laboratory model was used to compare the ability of 12 urease-positive species of urinary tract pathogens to encrust and block catheters. Proteus mirabilis, Proteus vulgaris and Providencia rettgeri were able to raise the urinary pH above 8.3 and produce catheter-blocking crystalline biofilms within 40 h. Morganella morganii and Staphylococcus aureus elevated the pH of urine to 7.4 and 6.9, respectively, and caused some crystal deposition in the biofilms but did not block catheters in the 96 h experimental period. Isolates of Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Serratia marcescens, Pseudomonas aeruginosa and Providencia stuartii were only capable of raising the pH of urine to a maximum of 6.4 and failed to cause crystal deposition in the biofilm. The most effective way to prevent catheter encrustation was shown to be diluting urine and increasing its citrate concentration. This strategy raises the nucleation pH (pH(n)) at which calcium and magnesium phosphates crystallize from urine. Increasing the fluid intake of a healthy volunteer with citrated drinks resulted in urine with a pH(n) of >8.0 in which catheter encrustation was inhibited. It is suggested that this dietary strategy will be an effective means of controlling catheter encrustation, whichever bacterial species is causing the problem.

Apolipoprotein B-associated cholesterol is a determinant of treatment outcome in patients with chronic hepatitis C virus infection receiving anti-viral agents interferon-alpha and ribavirin.

BACKGROUND: Hepatitis C virus (HCV) co-opts very-low-density lipoprotein (VLDL) pathways for replication, secretion and entry into hepatocytes and associates with apolipoprotein B (apoB) in plasma. Each VLDL contains apoB-100 and variable amounts of apolipoproteins E and C, cholesterol and triglycerides. AIM: To determine whether baseline lipid levels predicted treatment outcome. METHODS: Retrospective analysis was performed of 250 chronic hepatitis C (CHC) patients who had received anti-viral agents interferon-alpha and ribavirin; 165 had a sustained virological response (SVR). Pre- and post-treatment nonfasting lipid profiles were measured and non-high-density lipoprotein (non-HDL) cholesterol (i.e. apoB-associated) was calculated. Binary logistic regression analysis assessed factors independently associated with treatment outcome. RESULTS: There was an independent association between higher apoB-associated cholesterol (non-HDL-C) and increased odds of SVR (odds ratio 2.09, P = 0.042). In multivariate analysis, non-HDL-C was significantly lower in HCV genotype 3 (g3) than genotype 1 (P = 0.007); this was reversible upon eradication of HCVg3 (pre-treatment non-HDL-C = 2.8 mmol/L, SVR = 3.6 mmol/L, P < 0.001). CONCLUSIONS: Higher apoB-associated cholesterol is positively associated with treatment outcome in CHC patients receiving anti-viral therapy, possibly due to competition between apoB-containing lipoproteins and infectious low-density HCV lipo-viral particles for hepatocyte entry via shared lipoprotein receptors.

A study of the structure of the crystalline bacterial biofilms that can encrust and block silver Foley catheters.

The aim of this study was to examine the structure of the crystalline bacterial biofilms that encrust and block silver/hydrogel-coated latex catheters. Scanning electron microscopy was used to examine the crystalline deposits that were found encrusting catheters obtained from six patients undergoing long-term catheterization in a community setting. Large populations of bacilli and cocci were seen on all catheters developing on a basal foundation layer of crystalline material. These observations show that in patients prone to catheter encrustation, crystalline material formed in the urine can cover the surfaces of silver catheters. Extensive bacterial biofilms then develop on the crystals, shielded from the underlying silver. It is suggested that if antimicrobials are to be incorporated into catheters to prevent encrustation, they must diffuse out from the catheter surface and reduce the viable cell populations of the urease producing bacteria that elevate the urinary pH and trigger crystal formation.

Bcr-Abl induces autocrine IGF-1 signaling.

Bcr-Abl oncogene is responsible for the initial phase of chronic myelogenous leukemia (CML), which is effectively treated by the Bcr-Abl inhibitor imatinib. Over time patients become resistant to treatment and progress to blast crisis, an event that is driven by additional genetic and epigenetic aberrations. Recently, we showed that Riz1 expression decreases in blast crisis and that re-expression of Riz1 inhibits IGF-1 expression. IGF-1 signaling is required in many stages of hematopoiesis and inappropriate activation of autocrine IGF-1 signaling may facilitate transformation to blast crisis. We observed that in 8 out of 11 matched CML patient biopsies the IGF-1 expression is elevated in blast crisis. We examined mechanisms used by CML blast crisis cell lines to activate IGF-1 expression. We found that Bcr-Abl activates autocrine IGF-1 signaling using Hck and Stat5b. Inhibition of these signaling components using small molecule drugs or shRNA decreases proliferation and enhances apoptosis. Together, our study suggests that aberrant IGF-1 signaling is an important event in blast crisis transformation and it provides a mechanism to explain the activity of IGF-1R and Hck inhibitors in blocking CML blast crisis phenotypes.

Regions of alpha-amino-5-methyl-3-hydroxy-4-isoxazole propionic acid receptor subunits that are permissive for the insertion of green fluorescent protein.

The green fluorescent protein can be fused to the ends of a mature glutamate receptor subunit to produce functional, fluorescent receptors. However, there are good reasons to search for internal regions of receptor subunits that can tolerate green fluorescent protein insertion. First, internal insertions of green fluorescent protein may produce functional, fluorescent subunits that traffic more correctly. Second, fluorescent proteins inserted near interacting surfaces of subunits could potentially create reagents suitable for fluorescence resonance energy transfer measurements. Finally, internal green fluorescent protein insertions could potentially produce subunits capable of signaling conformational changes through intrinsic changes in fluorescence intensity. To identify regions of receptor subunits that are permissive for green fluorescent protein insertion, we used a series of recombinant transposons to create fluorescent protein insertions in three alpha-amino-5-methyl-3-hydroxy-4-isoxazole propionic acid receptor subunits. A combined analysis of the relative fluorescence intensity and glutamate-gated ion channel function of 69 different green fluorescent protein fusion proteins identified permissive zones for the creation of bright and fully functional receptor subunits in the C-terminal portion of the amino terminal domain, the intracellular tail of the carboxy terminal domain, and within the pore-forming regions of the channel.

Modulation of crystalline Proteus mirabilis biofilm development on urinary catheters.

The crystalline biofilms formed by Proteus mirabilis can seriously complicate the care of patients undergoing long-term bladder catheterization. The generation of alkaline urine by the bacterial urease causes calcium and magnesium phosphates to precipitate from urine and accumulate in the catheter biofilm, blocking the flow of urine from the bladder. The pH at which these salts crystallize from a urine sample, the nucleation pH (pH(n)), can be elevated by diluting the urine and by increasing its citrate content. The aim of this study was to examine whether manipulation of pH(n) in these ways modulated the rate at which crystalline biofilm developed. Experiments in laboratory models of the catheterized bladder infected with P. mirabilis showed that when the bladder was supplied with a concentrated urine (pH(n) 6.7) at a low fluid output (720 ml per 24 h), catheters blocked at 19-31 h. Diluting this urine 1:4 increased the pH(n) to 7.5 and models supplied with this urine at 2880 ml per 24 h took 110-137 h to block. When models were supplied with urine containing citrate at 1.5 mg ml(-1) or above (pH(n) 8.3-9.1), the catheters drained freely for the full 7 day experimental period. Scanning electron microscopy revealed that the catheter biofilms that developed in urine with high pH(n) values were devoid of crystalline formations. These observations should encourage a clinical trial to examine the effect of increasing a patient's fluid intake with citrate-containing drinks on the encrustation and blockage of catheters.

Investigation of the effects of physiological and vasodilation-induced autonomic activation on the QTc Interval in healthy male subjects.

AIMS: Drug-induced prolongation of the QTc interval is an important marker for potential proarrhythmic action. Prolongation of the QTc interval results from alteration of the ionic currents that regulate cardiac repolarisation. Such effects may result from direct drug action or alternatively they could also occur indirectly by drug-induced modulation of autonomic tone, which is known to regulate cardiac repolarization. This study examined the effects of physiological and drug-induced autonomic activation on heart rate, QT and QTc intervals. METHODS: We studied 29 healthy male subjects aged 18-30 years. Electrocardiographs were recorded before and during autonomic activation induced by mental activation, standing, exercise and glyceryl trinitrate (GTN) (0.5 mg sublingual)-induced vasodilation in the presence and absence of beta-blockade (atenolol 100 mg daily for 4 days). QT intervals were measured manually by electronic callipers and corrected using the Fridericia formula. RESULTS: Heart rates were significantly increased during mental arithmetic, standing, exercise and GTN and this effect was significantly attenuated by atenolol, except for mental activation. QTc intervals were significantly reduced on standing and exercise and this was significantly attenuated by atenolol during exercise. In contrast, GTN increased QTc intervals (Delta = 5.7 ms, confidence interval +/- 3.2 ms, P < 0.005) and this was not attenuated by atenolol. CONCLUSIONS: Alteration in QTc intervals may result from physiological manoeuvres and vasodilation, interventions known to induce autonomic activation. We suggest that QTc prolongation due to GTN is indirectly mediated and unlikely to carry any proarrhythmic effect. Understanding whether drug-induced QTc prolongation is directly or indirectly mediated may be important to determine any potential proarrhythmic risk.

Contribution of nitric oxide and prostanoids to the cardiac electrophysiological and coronary vasomotor effects of diadenosine polyphosphates.

We investigated the hypothesis that the coronary vasomotor and cardiac electrophysiological effects of diadenosine polyphosphates (Ap(n)A) are mediated via release of nitric oxide and prostanoids. Transmembrane right ventricular action potentials, refractory periods, and coronary perfusion pressure were recorded from isolated, Langendorff-perfused guinea pig hearts studied under constant flow conditions. The effects of threshold (1 nM) and maximal (1 microM) concentrations of diadenosine triphosphate (Ap3A), tetraphosphate (Ap4A), pentaphosphate (Ap5A), and hexaphosphate (Ap6A) were studied in the presence of nitric oxide (NO) synthase inhibitors [L-NG-nitroarginine methyl ester, 300 microM; or L-N5-(1-iminoethyl)ornithine, 30 microM] or cyclooxygenase inhibitors (indomethacin, 100 microM or meclofenamate, 10 microM). Inhibition of cyclooxygenase and NO synthase both prevented the increases in action potential duration and refractory periods seen in response to Ap(n)A. Cyclooxygenase inhibition altered the vasomotor effects of the Ap(n)A in a manner that was related to the structure of the Ap(n)A compound (the effects of Ap3A were attenuated and those of Ap4A and Ap5A were prevented, while those of Ap6A were not abolished.) Inhibition of NO synthase did not abolish the vasomotor responses. These results demonstrate the importance of nitric oxide and prostanoids in the cardiac responses to Ap(n)A and support the hypotheses that the coronary vasomotor responses to Ap(n)A are mediated via release of prostanoids, that this is related to the structure of the compound, and that the cardiac electrophysiological responses to Ap(n)A involve both nitric oxide and prostanoid release.

Reduced anisotropy of action potential conduction in left ventricular hypertrophy.

INTRODUCTION: The aim of this study was to determine if anisotropic action potential conduction was altered during development of left ventricular hypertrophy (LVH). METHODS AND RESULTS: Isolated guinea pig left ventricular preparations from hearts that had developed LVH were used to measure conduction velocity in longitudinal and transverse orientations to the fiber direction. A variable degree of LVH was induced by placing a ring around the ascending aorta for 50 to 250 days. Results were compared with an age-matched control group that underwent a similar operation but with no ring placement. LVH was measured as the heart-to-body-weight ratio (HBR), which correlated with an increase of mean myocyte cross-sectional area. Longitudinal conduction velocity (LCV) declined progressively as HBR increased (mean +/- SD: sham vs LVH: HBR 3.74 +/- 0.30 g/kg vs 4.53 +/- 0.52 g/kg; LCV 72.8 +/- 15.5 vs 63.6 +/- 11.1 cm/sec). Mean transverse conduction velocity (TCV) was greater in LVH compared with control (20.5 +/- 4.7 cm/sec vs 25.4 +/- 8.1 cm/sec), but there was no significance in the trend as a function of HBR. The anisotropic ratio (LCV/TCV) significantly declined as HBR increased. The time constant of the foot of the action potential was smaller in the transverse compared with the longitudinal dimension. There was no influence of hypertrophy. CONCLUSION: The decrease of LCV and reduction of the anisotropic conduction ratio suggest remodeling of the tissue in LVH. The consequences for the generation of arrhythmias are discussed.

Coronary vasomotor and cardiac electrophysiologic effects of diadenosine polyphosphates and nonhydrolyzable analogs in the guinea pig.

Platelet activation in heart disease is important owing to the effects of platelet-derived compounds on myocardial perfusion and cardiac electrophysiology. Diadenosine polyphosphates are secreted from platelets and present in the myocardium, but their electrophysiologic and vasomotor effects are incompletely understood. We used isolated guinea-pig hearts to study the effects of diadenosine triphosphate (Ap3A), tetraphosphate (Ap4A), pentaphosphate (Ap5A), and hexaphosphate (Ap6A) (10 pM-0.1 mM), comparing their actions to those of adenosine, adenosine triphosphate, and non-hydrolyzable Ap4A and Ap5A analogs. Diadenosine polyphosphates (0.1 nM-0.1 microM) transiently reduced coronary perfusion pressure, which recovered during the continued presence of the compounds. At concentrations greater than 0.1 microM effects were maximal and sustained (perfusion pressure decreased from 36.5+/-3.4 to 18.6+/-2.5 mm Hg, p < 0.001, with 1 microM Ap4A). The changes in action potential duration and refractory period developed slowly but were maintained (0.1 nM-1 microM). With 1 nM Ap4A, action potential duration increased from 170.6+/-2.6 to 187.3+/-3.8 ms, p < 0.05, and refractory period increased from 138.5+/-1.6 to 147.9+/-2.0 ms, p < 0.05. Ap4A and its analog reduced QRS duration (from 24.7+/-1.1 to 13.9+/-1.6 ms with 1 microM Ap4A, p < 0.05). P2-purinergic (adenosine triphosphate) receptor antagonism (suramin) reduced perfusion pressure but was without electrophysiologic effect. Other changes in coronary perfusion pressure and electrophysiologic variables associated with Ap4A were not seen in the presence of suramin. P1-(adenosine) antagonism (8-[p-sulfophenyl]theophylline) attenuated the electrophysiologic effects only. Diadenosine polyphosphates have potent cardiac electrophysiologic and coronary vasomotor effects via purinergic receptors, suggesting an important role during platelet activation in acute coronary syndromes.